Transport and Golgi organisation protein 1 is a novel tumour progressive factor in oral squamous cell carcinoma

Tumor lymphangiogenesis index reveals the immune landscape and immunotherapy response in lung adenocarcinoma

Background

Lymphangiogenesis (LYM) has an important role in tumor progression and is strongly associated with tumor metastasis. However, the clinical application of LYM has not progressed as expected. The potential value of LYM needs to be further developed in lung adenocarcinoma (LUAD) patients.

Methods

The Sequencing data and clinical characteristics of LUAD patients were downloaded from The Cancer Genome Atlas and GEO databases. Multiple machine learning algorithms were used to screen feature genes and develop the LYM index. Immune cell infiltration, immune checkpoint expression, Tumor Immune Dysfunction and Exclusion (TIDE) algorithm and drug sensitivity analysis were used to explore the correlation of LYM index with immune profile and anti-tumor therapy.

Results

We screened four lymphangiogenic feature genes (PECAM1, TIMP1, CXCL5 and PDGFB) to construct LYM index based on multiple machine learning algorithms. We divided LUAD patients into the high LYM index group and the low LYM index group based on the median LYM index. LYM index is a risk factor for the prognosis of LUAD patients. In addition, there was a significant difference in immune profile between high LYM index and low LYM index groups. LUAD patients in the low LYM index group seemed to benefit more from immunotherapy based on the results of TIDE algorithm.

Conclusion

Overall, we confirmed that the LYM index is a prognostic risk factor and a valuable predictor of immunotherapy response in LUAD patients, which provides new evidence for the potential application of LYM.

TANGO1 interacts with NRTN to promote hepatocellular carcinoma progression by regulating the PI3K/AKT/mTOR signaling pathway

Transport and Golgi organization 1 (TANGO1) also known as MIA3, belongs to the melanoma inhibitory activity gene (MIA) family together with MIA, MIA2 and OTOR; these members play different roles in different tumors, but the mechanism underlying TANGO1s effect on hepatocellular carcinoma (HCC) is unclear. Our study confirmed that TANGO1 is a promoter of HCC, In HCC cells, TANGO1 can promote proliferation, inhibit apoptosis, promote EMT. These changes were reversed after TANGO1 inhibition. We explored the molecular mechanism of TANGO1 and HCC and found that the promoting effect of TANGO1 on HCC related to neurturin (NRTN) and the PI3K/AKT/mTOR signaling pathway based on RNA-seq results. NRTN is not only related to neuronal growth, differentiation and maintenance but is also involved in a variety of tumorigenic processes, and PI3K/AKT/mTOR signaling pathway has been shown to be involved in HCC progression. We verified that TANGO1 interacts with NRTN in HCC cells using endogenous Co-IP and confocal localization, and both promote HCC progression by activating the PI3K/AKT/mTOR signaling pathway. Our results reveal the mechanism by which TANGO1 promotes HCC progression, suggesting that the TANGO1/NRTN axis may be a potential therapeutic target for HCC worthy of further investigation.

Research progress and clinical application prospects of miRNAs in oral cancer

Oral cancer is one of the most common malignant tumors worldwide, and it is also one of the most important and difficult clinical problems to be solved. Due to the regional differences in diet culture, some areas have taken the 'hardest hit' of oral cancer cases. However, the existing clinical treatment methods (surgery as the main treatment method, radiotherapy and chemotherapy as the auxiliary ones) do not have satisfactory treatment effects; therefore, new diagnosis and treatment methods need to be developed and utilized. Micro RNAs (miRNAs), as a class of substances that play an important regulatory role in the development of tumors, have an important value in the diagnosis and treatment of various tumors. At the same time, many miRNAs have obvious expression differences in oral cancer tissues compared to normal tissues. Therefore, they may have diagnostic and therapeutic effects on oral cancer. In this review, we evaluate the miRNAs that play a regulatory role in the development of oral cancer and those that are expected to be applied in the diagnosis and treatment of oral cancer. At the same time, we summarize the important challenges that need to be addressed, aiming to provide evidence and suggestions for the application of miRNAs in the diagnosis and treatment of oral cancer.

Searching for New Molecular Targets for Oral Squamous Cell Carcinoma with a View to Clinical Implementation of Precision Medicine

Head and neck cancer, including oral squamous cell carcinoma (OSCC), is the eighth most common malignancy globally and is characterized by local invasiveness and high nodal metastatic potential. The OSCC incidence is also increasing, and the number of deaths is also rising steadily in Japan. The development of molecular markers to eradicate OSCC is an urgent issue for humankind. The increase in OSCC despite the declining smoking rate may be due to several viral infections through various sexual activities and the involvement of previously unfocused carcinogens, and genetic alterations in individual patients are considered to be more complicated. Given this situation, it is difficult to combat OSCC with conventional radiotherapy and chemotherapy using cell-killing anticancer drugs alone, and the development of precision medicine, which aims to provide tailor-made medicine based on the genetic background of each patient, is gaining attention. In this review article, the current status of the comprehensive search for driver genes and biomarkers in OSCC will be briefly described, and some of the candidates for novel markers of OSCC that were found will be outlined.

Identification of oral squamous cell carcinoma markers MUC2 and SPRR1B downstream of TANGO

PURPOSE

Transport and Golgi organization protein 1 (TANGO) promotes angiogenesis and lymphangiogenesis in oral squamous cell carcinoma (OSCC). To elucidate the underlying mechanisms, this study aims to identify and characterize elements downstream of TANGO that mediate its involvement in OSCC.

METHODS

In this study, microarray analysis compared gene expression between control and TANGO-repressed HSC3 cells. Protein expression in 213 OSCC tissue samples was analyzed immunohistochemically.

RESULTS

TANGO repression decreased or increased expression of Mucin 20 (MUC20) and small proline-rich protein 1B (SPRR1B), respectively. MUC20 increased the growth and invasiveness of OSCC cells via altered matrix metalloproteinase (MMP)-2 and E-cadherin expression and c-met phosphorylation. MUC20 induced angiogenesis and lymphangiogenesis by activating vascular endothelial growth factors A and C. In well-differentiated OSCC, SPRR1B expression was high (P = 0.0091) and correlated with keratinization markers and promoted proliferation by inducing mitogen-activated protein kinase p38 phosphorylation. MUC20 expression correlated significantly with clinical stage (P = 0.0024), lymph node metastasis (P = 0.0036), and number of blood and lymph vessels (P < 0.0001). MUC20-expressing cases had a significantly worse prognosis than non-expressing cases (P < 0.0001).

CONCLUSION

MUC20 and SPRR1B located downstream of TANGO may be useful molecular markers for OSCC.

Mast cell chymase promotes angiogenesis and lymphangiogenesis mediated by activation of melanoma inhibitory activity gene family members in oral squamous cell carcinoma

Mast cells (MCs) are present in the tumor stroma, and MCs that express the mast cell‑specific proteases tryptase and chymase (MCTC) exhibit several tumor‑related functions. It was previously reported that melanoma inhibitory activity (MIA) gene family members, including MIA, MIA2, and transport and Golgi organization protein 1 (TANGO), possess oncogenic functions in oral squamous cell carcinoma (OSCC). However, the relationships between MCTC, and clinicopathological characteristics and activation of the MIA gene family in OSCC remain unknown. In the present study, the functional roles of MCTC in patients with OSCC were investigated using immunohistochemistry and reverse transcription‑quantitative PCR. In addition, the effects of extracellular chymase on oral cancer cells were examined. In patients with OSCC, MCTC density was significantly affected by tumor progression and nodal metastasis, and was correlated with vessel density. MCTC density was also correlated with MIA and MIA2 expression. In OSCC cells, extracellular chymase promoted the secretion of vascular endothelial growth factor family proteins, and the transmigration and adhesion of HSC3 cells to endothelial cells; knockdown of MIA, MIA2 and TANGO attenuated these effects. The present findings indicated that MCTC act as tumor‑progressive factors in OSCC via the activation and secretion of MIA and MIA2, and the induction of angiogenesis and lymphangiogenesis.

Non-SMC Condensin I Complex Subunit H (NCAPH) Is Associated with Lymphangiogenesis and Drug Resistance in Oral Squamous Cell Carcinoma

Background: Head and neck cancer, including oral squamous cell carcinoma (OSCC), is the sixth most common malignancy. OSCC has strong invasive ability, and its malignant potential is closely associated with local expansion and lymph node metastasis. Furthermore, local or nodal recurrence worsens OSCC prognosis. In our previous cDNA microarray analysis, non-structural maintenance of chromosome (SMC) condensin I complex subunit H (NCAPH) was identified as an upregulated gene in recurrent OSCC. Although NCAPH has several functions in tumors, its role in OSCC is unknown. Methods: In this study, we examined NCAPH expression in OSCC and performed a functional analysis of human OSCC cells. Results: NCAPH expression was higher in OSCC than in normal oral mucosa. In immunohistochemistry using 142 OSCC specimens, the immunostaining of NCAPH was strongly associated with nodal metastasis and lymphatic infiltration. In multivariate analysis using the Cox proportional hazards model, NCAPH expression was an independent poor prognostic indicator for OSCC. Moreover, NCAPH promoted the migration and adhesion of endothelial cells to OSCC cells and promoted the resistance to platinum anticancer drugs. Conclusions: Our present findings suggest that NCAPH is a novel diagnostic and therapeutic target in OSCC.

SPARC promotes the proliferation and metastasis of oral squamous cell carcinoma by PI3K/AKT/PDGFB/PDGFRβ axis

Oral squamous cell carcinoma (OSCC) is a highly lethal cancer in the world, and the prognosis of OSCC is poor with a 60% 5-year survival rate in recent decades. Here, we introduced a novel secretory and acid glycoprotein with cysteine rich (secreted protein acidic and rich in cysteine, SPARC), which is correlated with the worst pattern of invasion (WPOI) and prognosis of OSCC. SPARC expression levels were measured in OSCC tissues and normal tissues using quantitative polymerase chain reaction and immunohistochemistry. The influence of SPARC on cell proliferation was examined by cell counting kit-8, colony formation, and Edu tests. Then, the effect of SPARC on the metastasis of OSCC cells was detected by wound healing and transwell migration assays. Next, the biologic characteristics of SPARC shared by STRING were analyzed. Furthermore, the underlying mechanisms were confirmed by western blot analysis. SPARC revealed higher expression in OSCC tissues than nontumor tissues. Higher SPARC expression was correlated with poorer tumor differentiation, poorer WPOI pattern, and significantly and shorter overall survival. Knockdown SPARC significantly restrained OSCC cell growth, migration, and invasion. In addition, bioinformatics analysis found SPARC had a coexpression network with the platelet-derived growth factor-B (PDGFB) and PI3K/AKT signaling pathways with minimal false discovery rate. Furthermore, SPARC promotes OSCC cells metastasis by regulating the expressions of PDGFB, PDGFRβ, p-PDGFRβ , and the PI3K/AKT pathway. Higher SPARC expression was positively correlated with poor WPOI and differentiation in OSCC. SPARC activates the PI3K/AKT/PDGFB/PDGFRβ axis to promote proliferation and metastasis by OSCC cell lines. Therefore, SPARC may be a potential therapeutic target for patients with OSCC.

The Multifarious Functions of Pyruvate Kinase M2 in Oral Cancer Cells

Head and neck cancers, including oral squamous cell carcinoma (OSCC), are the sixth most common malignancies worldwide. OSCC frequently leads to oral dysfunction, which worsens a patient’s quality of life. Moreover, its prognosis remains poor. Unlike normal cells, tumor cells preferentially metabolize glucose by aerobic glycolysis. Pyruvate kinase (PK) catalyzes the final step in glycolysis, and the transition from PKM1 to PKM2 is observed in many cancer cells. However, little is known about PKM expression and function in OSCC. In this study, we investigated the expression of PKM in OSCC specimens and performed a functional analysis of human OSCC cells. We found that the PKM2/PKM1 ratio was higher in OSCC cells than in adjacent normal mucosal cells and in samples obtained from dysplasia patients. Furthermore, PKM2 expression was strongly correlated with OSCC tumor progression on immunohistochemistry. PKM2 expression was higher during cell growth, invasion, and apoptosis in HSC3 cells, which show a high energy flow and whose metabolism depends on aerobic glycolysis and oxidative phosphorylation. PKM2 expression was also associated with the production of reactive oxygen species (ROS) and integration of glutamine into lactate. Our results suggested that PKM2 has a variety of tumor progressive functions in OSCC cells.

Hallmarks of Cancer-Related Newly Prognostic Factors of Oral Squamous Cell Carcinoma

Head and neck cancer, including oral squamous cell carcinoma (OSCC), is the sixth leading malignancy worldwide. OSCC is an aggressive tumor and its prognosis has exhibited little improvement in the last three decades. Comprehensive elucidation of OSCC's molecular mechanism is imperative for early detection and treatment, improving patient survival. Based on broadly accepted notions, OSCC arises from multiple genetic alterations caused by chronic exposure to carcinogens. In 2011, research revealed 10 key alterations fundamental to cancer cell development: sustaining proliferative signaling, evading growth suppressors, avoiding immune destruction, activating invasion and metastasis, tumor-promoting inflammation, enabling replicative immortality, inducing angiogenesis, genome instability and mutation, resisting cell death, and deregulating energetics. This review describes molecular pathological findings on conventional and novel hallmarks of OSCC prognostic factors. In addition, the review summarizes the functions and roles of several molecules as novel OSCC prognosticators.

NIPA-like domain containing 1 is a novel tumor-promoting factor in oral squamous cell carcinoma

PURPOSE

In our previous global gene expression analysis, we identified NIPA-like domain containing 1 (NIPAL1), which encodes a magnesium transporter, as one of the most overexpressed genes in recurrent oral squamous cell carcinoma (OSCC). Although has been NIPAL1 linked with gout pathogenesis, little is known about its expression and function in human malignancies.

METHODS

In this study, we examined NIPAL1 expression in 192 cases of OSCC by immunohistochemistry and performed a functional analysis of human OSCC cells.

RESULTS

NIPAL1 immunostaining was observed in 39 of 192 OSCC patients (20.3%). NIPAL1 expression correlated significantly with cancer cell intravsation (P = 0.0062), as well as with poorer disease-free survival in a Kaplan-Meier analysis (P < 0.0001). Moreover, a multivariate Cox proportional hazards model analysis revealed that NIPAL1 expression was an independent predictor of disease-free survival in OSCC (P < 0.0001). In a functional analysis, NIPAL1 regulated the growth and adhesion of OSCC tumor cells and endothelial cells.

CONCLUSIONS

Our findings suggest that NIPAL1 might be a novel factor promoting OSCC tumorigenesis, as well as a useful molecular marker of OSCC.

The importance of melanoma inhibitory activity gene family in the tumor progression of oral cancer

Oral squamous cell carcinoma has a high potential for locoregional invasion and nodal metastasis. Consequently, early detection of such malignancies is of immense importance. The melanoma inhibitory activity (MIA) gene family comprises MIA, MIA2, transport and Golgi organization protein 1 (TANGO), and otoraplin (OTOR). These members of the MIA gene family have a highly conserved Src homology 3 (SH3)-like structure. Although the molecules of this family share 34-45% amino acid homology and 47-59% cDNA sequence homology, those members, excluding OTOR, play different tumor-associated functions. MIA has a pivotal role in the progression and metastasis of melanoma; MIA2 and TANGO have been suggested to possess tumor-suppressive functions; and OTOR is uniquely expressed in cochlea of the inner ear. Therefore, the definite functions of the MIA gene family in cancer cells remain unclear. Since the members of the MIA gene family are secreted proteins, these molecules might be useful tumor markers that can be detected in the body fluids, including serum and saliva. In this review, we described the molecular biological functions of the MIA gene family in oral cancer.

A comprehensive expression analysis of the MIA gene family in malignancies: MIA gene family members are novel, useful markers of esophageal, lung, and cervical squamous cell carcinoma

Melanoma inhibitory activity (MIA) gene family members include MIA, MIA2, and Transport and Golgi organization protein 1 (TANGO). Although MIA gene family members have several tumor-related functions, their detailed roles in malignancies remain poorly elucidated. In this study, 477 tumor specimens were subjected to immunohistochemical screening to evaluate MIA gene family expression. For a validation analysis, we also examined the association between MIA gene family expression and clinicopathological factors in 66 cases of esophageal cancer, 145 cases of lung cancer, and 126 cases of cervical cancer. The frequency of MIA gene family expression was higher among squamous cell carcinomas than among other tumor types subjected to screening. In the validation analysis, MIA gene family staining was observed frequently in esophageal and lung cancers associated with nodal and/or distant metastasis. In cervical cancers, MIA and TANGO immunostaining also correlated with tumor progression and metastasis. Furthermore, MIA2 expression levels in invasive cervical cancer were upregulated relative to those in cervical intraepithelial neoplasia 3. A disease-free survival analysis revealed that MIA-, MIA2, or TANGO-positive patients had a significantly shorter disease-free survival than did those patients who were negative. Our results suggest that MIA, MIA2, and TANGO may be useful diagnostic and therapeutic molecular targets in human malignancies.

Storkhead box 2 and melanoma inhibitory activity promote oral squamous cell carcinoma progression

Background

Storkhead box protein 2 (STOX2) is a transcriptional factor associated with pre-eclampsia with fetal growth restriction. We recently reported that melanoma inhibitory activity (MIA) promotes oral squamous cell carcinoma (OSCC) progression. However, the relationship between STOX2 and MIA remains unknown in malignancies.

Methods

We used immunohistochemistry and PCR to investigate MIA and STOX2 expression in OSCC. We also performed functional analysis in human OSCC cells.

Results

MIA and STOX2 mRNA levels were higher in OSCCs than in normal oral epithelial cells, and upregulation of STOX2 was significantly correlated with overexpression of MIA. Immunostaining for STOX2 was associated with nodal metastasis (P = 0.0002) and MIA expression (P < 0.0001). Furthermore, MIA expression (P = 0.0035) and STOX2 expression (P = 0.0061) were associated with poor outcome in OSCCs. In vitro analysis using OSCC cells revealed that MIA increased expression of STOX2 by paracrine manner. Moreover, STOX2 accelerated OSCC cell growth, invasion, suppressed apoptosis, and enhanced resistance to paclitaxel, cisplatin, and 5-FU.

Conclusions

Our results suggest that MIA-STOX2 signaling may be a useful diagnostic and therapeutic target in OSCCs.

Zinc finger AN1-type containing 4 is a novel marker for predicting metastasis and poor prognosis in oral squamous cell carcinoma

AIMS

Head and neck cancer, including oral squamous cell carcinoma (OSCC), is the sixth most common cancer worldwide and has a high potential for locoregional invasion and nodal metastasis. Therefore, discovery of a useful molecular biomarker capable of predicting tumour progression and metastasis of OSCC is crucial. We have previously reported zinc finger AN1-type containing 4 (ZFAND4) as one of the most upregulated genes in recurrent OSCC using a cDNA microarray analysis. Although ZFAND4 has been shown to promote cell proliferation of gastric cancer, its expression and clinicopathological roles in OSCC remain unclear.

METHODS

In this study, we examined ZFAND4 expression by immunohistochemistry in 214 cases of OSCC.

RESULTS

High cytoplasmic expression of ZFAND4 was observed in 45 out of 214 (21%) patients with OSCC. Expression levels of ZFAND4 were strongly associated with metastasis to the lymph nodes (p=0.0429) and distant organs (p=0.0068). Cases with high expression of ZFAND4 had a significantly unfavourable prognosis compared with patients with low expression of ZFAND4 (p<0.0001). Furthermore, ZFAND4 overexpression was an independent poor prognostic factor for OSCC as determined by multivariate analysis using the Cox proportional hazards model (p<0.0001).

CONCLUSIONS

These results suggest that ZFAND4 is a useful marker for predicting metastasis and poor prognosis in patients with OSCC.

Evidence for genetic association between chromosome 1q loci and predisposition to colorectal neoplasia

BACKGROUND

A substantial fraction of familial colorectal cancer (CRC) and polyposis heritability remains unexplained. This study aimed to identify predisposing loci in patients with these disorders.

METHODS

Homozygosity mapping was performed using 222 563 SNPs in 302 index patients with various colorectal neoplasms and 3367 controls. Linkage analysis, exome and whole-genome sequencing were performed in a family affected by microsatellite stable CRCs. Candidate variants were genotyped in 10 554 cases and 21 480 controls. Gene expression was assessed at the mRNA and protein level.

RESULTS

Homozygosity mapping revealed a disease-associated region at 1q32.3 which was part of the linkage region 1q32.2-42.2 identified in the CRC family. This includes a region previously associated with risk of CRC. Sequencing identified the p.Asp1432Glu variant in the MIA3 gene (known as TANGO1 or TANGO) and 472 additional rare, shared variants within the linkage region. In both cases and controls the population frequency was 0.02% for this MIA3 variant. The MIA3 mutant allele showed predominant mRNA expression in normal, cancer and precancerous tissues. Furthermore, immunohistochemistry revealed increased expression of MIA3 in adenomatous tissues.

CONCLUSIONS

Taken together, our two independent strategies associate genetic variations in chromosome 1q loci and predisposition to familial CRC and polyps, which warrants further investigation.

LEM domain containing 1 promotes oral squamous cell carcinoma invasion and endothelial transmigration

Background:

Oral squamous cell carcinomas have high potential for locoregional invasion and nodal metastasis. Thus, early detection and elucidation of detailed molecular mechanisms of OSCCs are important. Roles of LEM domain containing 1 (LEMD1), a novel cancer–testis antigen, in OSCCs are unclear.

Methods:

We performed immunohistochemical analysis of LEMD1 in 289 OSCC patients and examined functions of LEMD1 in these carcinomas.

Results:

Immunohistochemical analysis showed that 101 patients were positive for LEMD1. LEM domain containing 1 expression levels in OSCCs significantly correlated with tumour progression (T factor and clinical stage), nodal metastasis, and poor prognosis. LEM domain containing 1 expression was an independent predictor of disease-free survival in OSCC patients. In OSCCs, LEMD1 knockdown suppressed cancer cell invasion. Moreover, downregulation of LEMD1 expression inhibited adhesion and transmigration of OSCCs and vascular or lymphatic vascular endothelial cells.

Conclusions:

Our findings suggest that LEMD1 is a novel tumour progressive factor and may be a useful diagnostic and therapeutic target in OSCCs.

PDGFRβ Is a Novel Marker of Stromal Activation in Oral Squamous Cell Carcinomas

Carcinoma associated fibroblasts (CAFs) form the main constituents of tumor stroma and play an important role in tumor growth and invasion. The presence of CAFs is a strong predictor of poor prognosis of head and neck squamous cell carcinoma. Despite significant progress in determining the role of CAFs in tumor progression, the mechanisms contributing to their activation remain poorly characterized, in part due to fibroblast heterogeneity and the scarcity of reliable fibroblast surface markers. To search for such markers in oral squamous cell carcinoma (OSCC), we applied a novel approach that uses RNA-sequencing data derived from the cancer genome atlas (TCGA). Specifically, our strategy allowed for an unbiased identification of genes whose expression was closely associated with a set of bona fide stroma-specific transcripts, namely the interstitial collagens COL1A1, COL1A2, and COL3A1. Among the top hits were genes involved in cellular matrix remodeling and tumor invasion and migration, including platelet-derived growth factor receptor beta (PDGFRβ), which was found to be the highest-ranking receptor protein genome-wide. Similar analyses performed on ten additional TCGA cancer datasets revealed that other tumor types shared CAF markers with OSCC, including PDGFRβ, which was found to significantly correlate with the reference collagen expression in ten of the 11 cancer types tested. Subsequent immunostaining of OSCC specimens demonstrated that PDGFRβ was abundantly expressed in stromal fibroblasts of all tested cases (12/12), while it was absent in tumor cells, with greater specificity than other known markers such as alpha smooth muscle actin or podoplanin (3/11). Overall, this study identified PDGFRβ as a novel marker of stromal activation in OSCC, and further characterized a list of promising candidate CAF markers that may be relevant to other carcinomas. Our novel approach provides for a fast and accurate method to identify CAF markers without the need for large-scale immunostaining experiments.

Transcutaneous carbon dioxide suppresses epithelial-mesenchymal transition in oral squamous cell carcinoma

Oral squamous cell carcinoma (OSCC) is the most common form of oral cancers. Recent studies have shown that the malignant transformation of various carcinomas, including OSCC, is associated with epithelial-mesenchymal transition (EMT), and that expression of the EMT factors are significantly associated with tumor invasion, tumor metastasis, and survival rates in OSCC patients. Hence, there is a possibility that EMT suppression may improve the prognosis of OSCC patients. Hypoxia inducible factor-1α (HIF-1α) is a crucial microenvironmental factor in tumor progression, which induces the expression of EMT factors. We previously reported that transcutaneous CO2 suppresses both human OSCC tumor growth and metastasis to the regional lymph nodes by improving hypoxia in treated tissue. According to this background, we hypothesized that increased EMT with HIF-1α expression may increase the progression and the metastatic potential of OSCC, and that decreased hypoxia by transcutaneous CO2 could suppress EMT. In the present study, in vitro studies showed that hypoxic conditions increased the expression of HIF-1α and EMT factors in OSCC cells. In addition, in vivo studies revealed that transcutaneous CO2 increased E-cadherin expression with the decreased expression of HIF-1α, Snail, Slug, N-cadherin, and Vimentin in tumor treatment. These results suggest that transcutaneous CO2 could suppress EMT by improving hypoxia, resulting in the reduction of metastatic potential of OSCC. The findings indicate that transcutaneous CO2 may be able to improve the prognosis of OSCC patients through the suppression of EMT.

miR-185 mediates lung epithelial cell death after oxidative stress

Lung epithelial cell death is a prominent feature involved in the development of acute lung injury (ALI) and acute respiratory distress syndrome (ARDS). Hyperoxia-induced ALI is an established animal model mimicking human ARDS. Small noncoding RNAs such as microRNAs (miRNAs) have potent physiological and pathological functions involving multiple disease processes. Emerging interests focus on the potential of miRNAs to serve as novel therapeutic targets and diagnostic biomarkers. We found that hyperoxia highly induces miR-185 and its precursor in human lung epithelial cells in a time-dependent manner, and this observation is confirmed using mouse primary lung epithelial cells. The hyperoxia-induced miR-185 is mediated by reactive oxygen species. Furthermore, histone deacetylase 4 (HDAC4) locates in the promoter region of miR-185. We found that hyperoxia suppresses HDAC4 specifically in a time-dependent manner and subsequently affects histone deacetylation, resulting in an elevated miR-185 transcription. Using MC1586, an inhibitor of class IIa HDACs, we showed that inhibition of class IIa HDACs upregulates the expression of miR-185, mimicking the effects of hyperoxia. Functionally, miR-185 promotes hyperoxia-induced lung epithelial cell death through inducing DNA damage. We confirmed functional roles of miR-185 using both the loss- and gain-of-function approaches. Moreover, multiple 14-3-3δ pathway proteins are highly attenuated by miR-185 in the presence of hyperoxia. Taken together, hyperoxia-induced miR-185 in lung epithelial cells contributes to oxidative stress-associated epithelial cell death through enhanced DNA damage and modulation of 14-3-3δ pathways.